This invention relates generally to an engine, and more particularly, to a method and apparatus for controlling the speed of an engine.
Electronic control of fuel systems on an engine generally provide a determined amount of fuel to the engine in response to a desired and an actual engine speed. In one embodiment, the engine may have an associated turbocharger. When the load on the engine is quickly removed, an engine overspeed or turbo surge may result. That is, when the load is removed suddenly from the engine, the engine may rapidly accelerate above the desired engine speed. The speed of the engine and the turbocharger may begin to surge uncontrollably. Current fuel control systems may be unable to stabilize the engine speed, in part, because of the sudden and significant difference between the desired and actual engine speed.
The present invention is directed to overcoming one or more of the problems identified above.
In one aspect of the present invention, a method for controlling the speed of an engine is disclosed. The engine has an associated turbocharger and a throttle. The method includes the steps of determining a load characteristic of the engine, and controlling the engine in response to the load characteristic.
In another aspect of the present invention, an apparatus for controlling the speed of an engine is disclosed. The apparatus comprises a speed sensor adapted to sense a characteristic of the engine and responsively generate a speed signal indicative of the speed of the engine, and a controller adapted to receive the speed signal, determine a load characteristic of the engine, determine a change in the load characteristic, and control the engine in response to the load change.